The present invention relates to a leak indicating device for a magnetic centrifugal pump, and more particularly to such a pump having two separating pots with collars inserted one within another which seal against the pumped medium.
DE-B 18 00 018 discloses a hydraulic membrane pump which has three abutting individual membranes separating the delivery space and the hydraulic space. The central membrane has slots which are filled with hydraulic liquid. If a membrane is damaged, delivery medium or hydraulic medium reaches these slots and forces the liquid situated therein into a container disposed outside the pump where it triggers a signal device.
This leak indicating device was developed and is suitable primarily for membrane pumps. Its principal disadvantage is that the space between the outer two membranes must always be filled with liquid under pressure so as to hydraulically couple the membranes. This, unfortunately, requires considerable technical expense.
Some magnetic centrifugal pumps, on the other hand, have two separating pots inserted within one another. The inner separating pot comprises a chemically resistant plastic material and the outer separating pot comprises a fiber composite material.
When the inner pot is damaged by erosion or solids in the medium being pumped, the damage becomes apparent only when the outer pot and the metal shell are destroyed by the highly-aggressive, toxic or corrosive media and the medium is conveyed into the environment under the pressure of the operating pump.